The Mean Girls actress and her husband Dave Nehdar, whom she married in 2013, welcomed daughter Julia Mimi Bella into the world last week and the 33-year-old star hailed the tot's birth as the 'best day' of her life.

She shared a picture of the baby on Instagram on Thursday and wrote: 'And then my soul saw you and it kind of went, "Oh, there you are. I've been looking for you." #TBT to the best day of my life. One week ago I became a mom to this precious angel. Julia Mimi Bella.

First picture: Lacey Chabert welcomed daughter Julia Mimi Bella into the world last week

'Julia, you are my heart's deepest dream come true. I love you more than I could ever say. Welcome to this big beautiful world sweet girl!'

The Party of Five actress admitted recently she felt like she would be pregnant 'forever'.

She joked on social media: '#47weekspregnant OK not really, but seriously, for real...am I going to be pregnant forever? Is this a thing that happens to some women?? This last week and a half or so is no joke! #pleasecomesoonlittlelady #readytopop.'

Proud: The Mean Girls actress, seen here in May, said the arrival of her daughter was the 'best day' of her life

Lacey revealed her pregnancy in February with the help of her dog.

The actress uploaded a photograph of her pet pooch Kitty - who she calls her 'first child' - wearing a white pint-sized T-shirt emblazoned with the words, 'My mom is having a baby & all I get is this silly shirt (sic)', across the back.

She captioned the hilarious shot, which saw the adorable Chihuahua frowning at the camera: 'Kitty doesn't seem as excited about this as we are ... I'm pregnant!!!! My husband and I are thrilled & so thankful.'